108 lines
1.9 KiB
Go
108 lines
1.9 KiB
Go
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package main
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import (
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"fmt"
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"strconv"
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)
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func reverseSlice(slice []uint) {
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for i, j := 0, len(slice)-1; i < j; i, j = i+1, j-1 {
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slice[i], slice[j] = slice[j], slice[i]
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}
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}
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func compressedProgram(ra uint) []uint {
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out := make([]uint, 0)
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var A, B uint
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A = ra
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for {
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B = ((A % 8) ^ 2) ^ 7 ^ (A >> ((A % 8) ^ 2))
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A = A >> 3
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out = append(out, B%8)
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if A == 0 {
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break
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}
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}
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return out
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}
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func reversedProgram(out []uint) uint {
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reverseSlice(out)
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A := uint(0)
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for _, o := range out {
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// find next n bits so that o is returned
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n := 2
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searching := true
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for searching {
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n++
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// for every combination of n bits
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for i := range 1 << n {
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A_ := (A << n) + uint(i)
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//fmt.Println("add", i, "as binary with", n, "bits")
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//fmt.Println("old", strconv.FormatUint(uint64(A), 2))
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//fmt.Println("new", strconv.FormatUint(uint64(A_), 2))
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if o == ((A_%8)^2)^7^(A_>>((A_%8)^2))%8 {
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A = A_
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//fmt.Println("valid")
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//fmt.Println("yields", compressedProgram(A))
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searching = false
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break
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}
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//fmt.Println("invalid")
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}
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}
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}
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return A
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}
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func main() {
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/*
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fmt.Println(input)
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a := uint64(0)
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for _, elem := range input {
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expected_d := elem ^ 7
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for b := range 8 {
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e := uint64(b ^ 2)
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c := (((a << 3) | uint64(b)) >> (e)) % 8
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actual_d := c ^ e
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if uint64(expected_d) == actual_d {
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fmt.Println(b)
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fmt.Println(e)
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fmt.Println(c)
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a = a << 3
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a = a | uint64(b)
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fmt.Println(strconv.FormatUint(a, 2))
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fmt.Println(a, 2)
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break
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}
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}
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}
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fmt.Println(a)
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//fmt.Println(strconv.FormatUint(a, 2))
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*/
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//fmt.Println(compressedProgram(41644071))
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input := []uint{2, 4, 1, 2, 7, 5, 1, 7, 4, 4, 0, 3, 5, 5, 3, 0}
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fmt.Println("-- input: ", input, "--")
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ra := reversedProgram(input)
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fmt.Println("-- ra: ", ra, "--")
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}
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